Method for Preparing Resin Compositions Containing Nano Silver Particles

ABSTRACT

The present invention relates to synthetic resin composition containing nano silver particles, in which a silver complex having a specific structure that allows formation of the nano silver particles is dissolved in monomer for the resin composition and the organic silver complex is decomposed with polymerization to prepare the synthetic resin composition containing the nano silver particles. The present invention can provide a method for resin compositions, which has simple and economic preparation process and allows uniform dispersion of the nano silver particles in the resin composition.

TECHNICAL FIELD

The present invention relates to synthetic resin composition containingnano silver particles and a method for preparing the same, and moreparticularly, to a method for preparing a synthetic resin compositioncontaining nano silver particles in which a silver complex having aspecific structure that allows formation of the nano silver particles isdissolved in monomer for the resin composition and the organic silvercomplex is decomposed with polymerization to prepare the synthetic resincomposition containing the nano silver particles and nano silverparticles prepared therefrom.

BACKGROUND ART

In general, a synthetic resin composition is used as a raw material in avariety of fields including household supplies, synthetic fibers,filters, electronic materials and the like and requires functionalreinforcement. As is well known, silver is a noble metal, which has notoxicity to humans and removes toxins. Also, the silver is known as asuperior natural antibiotic which neutralizes enzymes related metabolismof 650 or more species of pathogenic microorganisms including bacteria,viruses and mold and thus has an excellent effect on fungi and virusesas well as bacteria uncontrollable by general antibiotics. Therefore, aresin composition containing nano silver particles may be usefully usedas an antibiotic resin, an antistatic resin, an electromagnetic waveshielding resin or the like.

The antibiotic resin composition may be utilized as a container for foodand beverage, water supplying pipe, a container for a refrigerator, awater tank of a humidifier, a medical container and the like. Also, theresin composition containing nano silver particles dispersed therein maybe effectively used as a material for electromagnetic wave shielding inelectronic appliances and also widely used as a resin composition forpreventing static electricity in home electronics.

In recent, there have been made many efforts to achieve cost reductionand simplified process in preparation of the resin compositioncontaining the nano silver particles by increasing an affinity of thenano silver particles for the synthetic resin composition.

The resin composition containing the nano silver particles may beprepared by a variety of methods. In one example, Korean PatentPublication No. 2005-0047029 discloses a method of dispersing the nanosilver particles using a physical force, in which, in a super mixer,polypropylene (PPJ700, Hyosung Corp., Korea) is put and rotated for 40minutes with the temperature being increased to 55 to 65° C., nanosilver particles colloidal solution is then put and rotated again for 20to 30 minutes, and a wax (product name: X861, Bayer) is put as adispersing agent and further rotated for 5 to 10 minutes to prepare theresin containing nano silver particles. In another example, KoreanPatent Publication No. 2005-0079261 discloses a method of preparing aresin composition containing nano silver particles, in which aconventionally used mixer is heated to be maintained at a constanttemperature, and a mixture of an general purpose plastic such as PVC andPE, an engineering plastic such as PET and PC and highly concentratedtransparent colloidal silver aqueous solution is then put in the mixerand kneaded with stirring, followed by the extrusion by an extruderwhile the temperature being maintained suitably at 150 to 300° C. andcutting the extruded product to a predetermined size and shape.

In further another example, Korean Patent Publication No. 2003-0003203discloses a method of preparing a resin composition containing nanosilver particles, in which a synthetic resin composition, silver powderand aluminum powder are mixed and heated to a temperature of 180 to 230°C., followed by stirring by a stirrer to melt mix the silver powder.

According to the conventional methods as described above, a polymerresin composition is previously obtained from a monomer and thendispersed in colloidal solution or solid powder of nano silver particleswhich has been also previously prepared. Therefore, there aredisadvantages that the preparation process is complex and uneconomicsince a dispersing agent is needed to facilitate the dispersion and aphysical force, e.g. an extruder, a melter, a stirrer or a super mixeris also needed.

Further, Korean Patent Publication No. 2003-0049007 discloses a methodof preparing a resin composition containing silver particles by mixing acolloidal solution of nano-sized silver, monomers for a resincomposition, an emulsifier and an initiator and then performing emulsionpolymerization, suspension polymerization or microemulsionpolymerization.

However, since the colloidal solution of nano silver particles is usedin this method, an emulsifier or a dispersing agent is needed tofacilitate the dispersion of the nano silver particles and there is alimitation in uniformity of the nano silver particles dispersed in theresin composition.

Meanwhile, Korean Patent Publication No. 2003-0031090 discloses a methodof preparing unsaturated polyester composite containing nano silverparticles, in which silver salt such as silver nitrate and silveracetate is dissolved in polar solvent such as acetonitrile and ethyleneglycol and mixed with unsaturated polyester resin composition containingstyrene monomer, followed by curing by a radical initiator and anaccelerator to prepare the unsaturated polyester composite containingnano silver particles. This method is characterized in that silver ionis reduced and grown to the nano silver particles during radicalpolymerization. However, polar solvent for dissolving the silver salt isnecessarily required since the silver salt such as silver nitrate andsilver acetate is used and it is difficult to prepare a resincomposition in which the nano silver particles are dispersed with highconcentration since there is a limitation in uniformity anddispersibility of the nanoparticles contained in the polymer resincomposition.

DISCLOSURE Technical Problem

An object of the present invention is to provide a method for preparingsynthetic resin compositions containing uniformly dispersed nano silverparticles, in which a precursor, i.e. an organic silver complex, whichallows formation of the nano silver particles is dissolved in a monomerto be polymerized to the resin composition and the organic silvercomplex is decomposed to form the nano silver particles duringpolymerization, unlike the conventional methods in which nano silverparticles are dispersed in a previously synthesized polymer resin.

Another object of the present invention is to provide a preparationmethod, which does not use a separate physical dispersing device ordispersing agent and thus has simple and economic preparation process.

The present applicant has confirmed that silver is transformed to astable silver complex in a form of a composite with ammonium carbonateor ammonium carbamate by reacting the ammonium carbonate or ammoniumcarbamate with a silver compound such as silver oxide and separated in asolid form, and silver thin film or nanoparticles may be easily preparedfrom the produced silver complex. This is disclosed in Korean PatentApplication No. 2006-0011083 and Korean Patent Application No.2006-0074246 by the present applicant.

The present inventors have confirmed that, when using the silver complexdisclosed in the aforementioned applications, since there is no need fora polar solvent, which has been required when using silver salt such assilver nitrate and silver acetate in the conventional methods, thesilver complex can be directly dissolve in various vinyl monomers andalso silver particles having a size from several to tens nm areuniformly formed and dispersed in a synthetic resin composition withhigh concentration as the silver complex is gradually decomposed andreduced to silver particles during radical polymerization or subsequentheat treatment, and have achieved the present invention therefrom.

Therefore, an object of the present invention is to provide a method forpreparing resin compositions containing nano silver particles, in whichnano silver particles dispersed in the resin have uniform sizes and highdispersibility and can be dispersed in the resin with high concentrationby using a silver complex having a specific structure which is highlystable and highly soluble in various vinyl monomers and decomposed at alow temperature to easily form nano silver particles.

Technical Solution

To achieve the above and other objects, the present invention provides amethod for preparing resin compositions containing nano silverparticles, which includes dissolving a silver complex having a specificstructure in at least one vinyl monomer; and polymerizing the vinylmonomer.

The silver complex used in the present invention is prepared by reactinga silver compound represented by the formula 1 with one or a mixture oftwo or more selected from the group consisting of ammoniumcarbamate-based compound, ammonium carbonate-based compound and ammoniumbicarbonate-based compound represented by the formula 2 to 4.

The silver complex is a stable silver complex in a form of a compositewith ammonium carbonate or ammonium carbamate by adding the ammoniumcarbonate or the ammonium carbamate to a compound such as silver oxideand the silver complex is decomposed and separated as solids by heatingto produce nano silver particles.

wherein, in the formulas 1 to 4, X is a substituent selected from thegroup consisting of oxygen, sulfur, halogen, cyano, cyanate, carbonate,nitrate, nitrite, sulfate, phosphate, thiocyanate, chlorate,perchlorate, tetrafluoroborate, acetylacetonate, carboxylate andderivatives thereof, n is an integer from 1 to 4, and R₁ to R₆ areindependently selected from the group consisting of hydrogen, hydroxylgroup, C₁-C₃₀ alkoxy group, C₃-C₂₀ aryloxy group, C₁-C₃₀ aliphatic orC₃-C₂₀ cycloaliphatic alkyl group or aryl or C₄-C₃₀ aralkyl group as amixture thereof, substituted C₁-C₃₀ alkyl group, substituted C₃-C₂₀ arylgroup, substituted C₄-C₃₀ aralkyl group, C₃-C₂₀ heterocyclic compoundincluding a heteroatom selected from the group consisting of N, S and O,polymer compound and derivatives thereof, wherein when R₁ to R₆ aresubstituted or unsubstituted alkyl group or aralkyl group, alkyl groupor aralkyl group may contain a heteroatom selected from the groupconsisting of N, S and O, or an unsaturated bond in the carbon chain,wherein R₁ and R₂ or R₄ and R₅, independently, may form an alkylene ringcontaining or not containing a heteroatom.

Examples for the substituted functional group may include, but notlimited to, C₁-C₃₀ alkoxy group, carboxyl group, tri(C₁-C₇)alkoxysilylgroup, hydroxyl group and cyano group.

Specific examples for the compound of the formula 1 are, but not limitedto, silver oxide, silver thiocyanate, silver sulfide, silver chloride,silver cyanide, silver cyanate, silver carbonate, silver nitrate, silvernitrite, silver sulfate, silver phosphate, silver perchlorate, silvertetrafluoroborate, silver acetylacetonate, silver acetate, silverlactate, silver oxalate or a derivative thereof.

Also, specific examples for the substituents R₁ to R₆ of the formulas 2to 4 may be selected from, but not particularly limited to, the groupconsisting of hydrogen, methyl, ethyl, propyl, isopropyl, butyl,isobutyl, amyl, hexyl, ethylhexyl, heptyl, octyl, isooctyl, nonyl,decyl, dodecyl, hexadecyl, octadecyl, docodecyl, cyclopropyl,cyclopentyl, cyclohexyl, allyl, hydroxy, methoxy, hydroxyethyl,methoxyethyl, 2-hydroxypropyl, methoxypropyl, cyanoethyl, ethoxy,butoxy, hexyloxy, methoxyethoxyethyl, methoxyethoxyethoxyethyl,hexamethyleneimine, morpholine, piperidine, piperazine, ethylenediamine,propylenediamine, hexamethylenediamine, triethylenediamine, pyrrole,imidazole, pyridine, carboxymethyl, trimethoxysilylpropyl,triethoxysilylpropyl, phenyl, methoxyphenyl, cyanophenyl, phenoxy,tolyl, benzyl and a derivative thereof, a polymer compound such aspolyallylamine and polyethyleneimine and a derivative thereof.

In specific examples of the compound, the ammonium carbamate-basedcompound represented by the formula 2 may be one or a mixture of two ormore selected from the group consisting of ammonium carbamate,ethylammonium ethylcarbamate, isopropylammonium isopropylcarbamate,n-butylammonium n-butylcarbamate, isobutylammonium isobutylcarbamate,t-butylammonium t-butylcarbamate, 2-ethylhexylammonium2-ethylhexylcarbamate, octadecylammonium octadecylcarbamate,2-methoxyethylammonium 2-methoxyethylcarbamate, 2-cyanoethylammonium2-cyanoethylcarbamate, dibutylammonium dibutylcarbamate,dioctadecylammonium dioctadecylcarbamate, methyldecylammoniummethyldecylcarbamate, hexamethyleneiminium hexamethyleneiminecarbamate,morpholinium morpholinecarbamate, pyridinium ethylhexylcarbamate,triethylenediaminium isopropylbicarbamate, benzylammoniumbenzylcarbamate, triethoxysilylpropylammoniumtriethoxysilylpropylcarbamate and a derivative thereof. The ammoniumcarbonate-based compound represented by the formula 3 may be one or amixture of two or more selected from the group consisting of ammoniumcarbonate, ethylammonium ethylcarbonate, isopropylammoniumisopropylcarbonate, n-butylammonium n-butylcarbonate, isobutylammoniumisobutylcarbonate, t-butylammonium t-butylcarbonate,2-ethylhexylammonium 2-ethylhexylcarbonate, 2-methoxyethylammonium2-methoxyethylcarbonate, 2-cyanoethylammonium 2-cyanoethylcarbonate,octadecylammonium octadecylcarbonate, dibutylammonium dibutylcarbonate,dioctadecylammonium dioctadecylcarbonate, methyldecylammoniummethyldecylcarbonate, hexamethyleneiminium hexamethyleneiminecarbonate,morpholinium morpholinecarbonate, benzylammonium benzylcarbonate,triethoxysilylpropylammonium triethoxysilylpropylcarbonate,triethylenediaminium isopropylcarbonate and a derivative thereof. Theammonium bicarbonate-based compound represented by the formula 4 may beone or a mixture of two or more selected from the group consisting ofammonium bicarbonate, isopropylammonium bicarbonate, t-butylammoniumbicarbonate, 2-ethylhexylammonium bicarbonate, 2-methoxyethylammoniumbicarbonate, 2-cyanoethylammonium bicarbonate, dioctadecylammoniumbicarbonate, pyridinium bicarbonate, triethylenediaminium bicarbonateand a derivative thereof.

Meanwhile, methods of preparing the ammonium carbamate-based compound,ammonium carbonate-based compound and ammonium bicarbonate-basedcompound are not particularly limited. For example, U.S. Pat. No.4,542,214 (Sep. 17, 1985) discloses that ammonium carbamate compound canbe prepared from primary amine, secondary amine, tertiary amine or amixture of at least one thereof and carbon dioxide. Ammoniumcarbonate-based compound may be obtained if 0.5 mole of water is addedper 1 mole of amine, and ammonium bicarbonate-based compound may beobtained when 1 mole or more of water is added. The preparation may beperformed under atmospheric or increased pressure without a solvent, orin the presence of such solvent as water, alcohols like methanol,ethanol, isopropanol and butanol, glycols like ethylene glycol andglycerine, acetates like ethyl acetate, butyl acetate and carbitolacetate, ethers like diethyl ether, tetrahydrofuran and dioxane, ketoneslike methyl ethyl ketone and acetone, hydrocarbons like hexane andheptane, aromatic hydrocarbons like benzene and toluene andhalogen-substituted solvents like chloroform, methylene chloride andcarbon tetrachloride. The carbon dioxide may be bubbled in gas phase orused in the form of dry ice.

Alternatively, the preparation may be performed in the supercriticalphase. Any other known methods can be applied in the preparation of theammonium carbamate-based, ammonium carbonate-based or ammoniumbicarbonate-based compound used in the present invention, provided thatthe final structure is the same. That is, solvent, reaction temperature,concentration, catalyst, etc. are not particularly limited in thepreparation. Nor the preparation yield is particularly limited.

The amount of silver complex is 0.01 to 5 wt %, preferably 0.05 to 1 wt% for total weight of a mixture of vinyl monomer and the silver complex.An effect due to nano silver particles, i.e. antibiotic effect,electromagnetic wave shielding effect or an antistatic effect isinsignificant when the content of the silver complex is less than 0.01wt %, and it is uneconomic as the effect is insignificantly increasedand physical properties of polymer resin may be affected when thecontent of the silver complex is more than 5 wt %. Also, solubility inmonomer is determined by a length of alkyl chain (R₁ to R₆) in ammoniumgroup. As the length of the alkyl chain becomes longer, hydrophobia isincreased to increase solubility in non-polar monomer such as styreneand, as the length of the alkyl chain becomes shorter and branches aremore increased, solubility in polar monomer such as vinylpyrrolidone isincreased. Particularly, upon production of nano silver particles anddecomposition of ammonium carbamate-based, ammonium carbonate-based andammonium bicarbonate-based compound at a polymerization temperature, itis preferred to be highly volatile to facilitate removal.

The vinyl monomer is a monomer which allows radical polymerization andmay be selected according to the use or the purpose. Therefore, the sortof the vinyl monomer is not particularly limited, but is preferred to behighly soluble in silver complex. The vinyl monomer may be introduced byan amount of 95 to 99.99 wt %, preferably 99 to 99.95 wt % though itdepends on the structure of the silver complex and the solubility of thevinyl monomer according to the polarity thereof. The vinyl monomer maybe one or a mixture of two or more selected from alkyl group-containingvinyl monomers like methylacrylate, methylmethacrylate, ethylacrylate,ethylmethacrylate, propylacrylate, propylmethacrylate, butylacrylate,butylmethacrylate, hexylacrylate, hexylmethacrylate, octylacrylate,2-ethylhexylacrylate; hydroxyethylacrylate, hydroxyethylmethacrylate,hydroxypropylacrylate, hydroxypropylmethacrylate, hydroxybutylacrylate,hydroxybutylmethacrylate, hydroxyhexylacrylate,hydroxyhexylmethacrylate; N-substituted amide-based vinyl monomers likeN,N-dimethylacrylamide and N,N-dimethylmethacrylamide;alkoxyalkylacrylate-based vinyl monomers like methoxyethylacrylate,methoxyethylmethacrylate, ethoxyethylacrylate andethoxyethylmethcrylate; vinyl monomers like vinylchloride, vinylidenechloride, vinylfluoride, vinylidene fluoride, vinylacetate,vinylpropionate, N-vinylpyrrolidone, methylvinylpyrrolidone,vinylpyridine, vinylpiperidone, vinylpyrimidine, vinylpiperazine,vinylpyrazine, vinylpyrrole, vinylimidazole, vinyloxazole,vinylmorpholine, N-vinylcarboxamides, styrene, α-methylstyrene, andN-vinylcaprolactam; cyanoacrylate monomers like acrylonitrile andmethacrylonitrile; epoxy group-containing acrylic monomers likeglycidylacrylate and glycidylmethacrylate; glycol acrylester monomerslike ethyleneglycolacrylate, ethyleneglycolmethacrylate,propyleneglycolacrylate, propyleneglycolmethacrylate,methoxyethyleneglycolacrylate, methoxyethyleneglycolmethacrylate,methoxypropyleneglycolacrylate and methoxypropyleneglycolmethacrylate;acrylic acid ester monomers like tetrahydrofurfuryl acrylate,tetrahydrofurfuryl methacrylate and 2-methoxyethyl acrylate; andmonomers like isoprene, butadiene, isobutylene, vinyl ether,diallylphthalate and diallylcarbonate.

The silver complex is dissolved in at least one aforementioned vinylmonomer and then radically polymerized.

The radical polymerization may include known methods such as bulkpolymerization, suspension polymerization, solution polymerization andemulsion polymerization, but not particularly limited thereto. Also, aradical polymerization initiator may be selected from the groupconsisting of α,α′-azobisisobutyronitrile (AIBN), dibenzoylperoxide,tertiarybutylperoxybenzoate, ditertiarybutylperoxide,tertiarybutylperoxy 2-ethylhexanoate, cumylhydroperoxide,dicumylperoxide and tertiarybutylhydroperoxide.

During the radical polymerization, the silver complex is decomposed andsilver ion is reduced to form nano silver particles. If necessary, heattreatment may be performed after the polymerization. The heat treatmentmay be performed by any known heat treating methods and preferablyperformed at 40 to 200° C., more preferably 80 to 150° C. Though thereaction for decomposition and reduction of the silver complex may beperformed at a temperature below 40° C. or above 200° C., reductionspeed is low at below 40° C. and the heat treatment temperature isunnecessarily high at above 200° C.

DESCRIPTIN OF DRAWINGS

The above and other objects, features and advantages of the presentinvention will become apparent from the following description ofpreferred embodiments given in conjunction with the accompanyingdrawings, in which:

FIG. 1 is a Transmission Electron Microscope (TEM) photographillustrating polymethylmethacrylate (PMMA) containing nano silverparticles of Example 4 of the present invention; and

FIG. 2 is a TEM photograph illustrating polyvinylpyrrolidone (PVP)containing nano silver particles of Example 6 of the present invention.

BEST MODE

Practical and presently preferred embodiments of the present inventionare illustrative as shown in the following Examples.

However, it will be appreciated that those skilled in the art, onconsideration of this disclosure, may make modifications andimprovements within the spirit and scope of the present invention.

Preparation Examples Preparation of silver Complex

Silver complexes were prepared using silver compound and ammoniumcompound as described in the following Preparation Examples.

Preparation Example 1

In a 50 mL Schlenk flask equipped with a stirrer, 3.25 g (10.75 mmol) of2-ethylhexylammonium 2-ethylhexylcarbamate (viscous liquid) wasdissolved in 10 mL of methanol. 1.0 g (4.31 mmol) of silver oxide wasadded and reaction was performed at room temperature. The reactionsolution was initially a black slurry but it turned transparent ascomplex was produced. After 2 hours of reaction, a colorless,transparent solution was obtained. The resultant solution was filteredwith a 0.45 micron membrane filter to remove unreacted silver oxide.Then, the solvent was removed under vacuum to obtain white solid. Thesolid was recrystallized in ethyl acetate, dried and weighed to obtain4.22 g of a silver complex (yield=99.4%).

Preparation Example 2

In a 50 mL Schlenk flask equipped with a stirrer, 3.72 g (11.61 mmol) of2-ethylhexylammonium 2-ethylhexylcarbonate (viscous liquid) wasdissolved in 10 mL of methanol. 1.0 g (4.31 mmol) of silver oxide wasthen added. The reaction solution was initially a black slurry but itturned transparent as the reaction was performed. After 2 hours ofreaction, a colorless, transparent solution was obtained. The resultantsolution was filtered with a 0.45 micron membrane filter to removeunreacted silver oxide. Then, the solvent was removed under vacuum toobtain white solid. The solid was dried and weighed to obtain 4.02 g ofa silver complex (yield=85.2%).

Preparation Example 3

In a 50 mL Schlenk flask equipped with a stirrer, 4.86 g (25.37 mmol) of2-ethylhexylammonium bicarbonate (viscous liquid) was dissolved in 10 mLof methanol. 1.0 g (4.31 mmol) of silver oxide was then added. Thereaction solution was initially a black slurry but it turned transparentas the reaction was performed. After 2 hours of reaction, a colorless,transparent solution was obtained. The resultant solution was filteredwith a 0.45 micron membrane filter. Then, the solvent was removed undervacuum to obtain white solid. The solid was dried and weighed to obtain4.33 g of a silver complex (yield=73.9%).

Preparation Example 4

In a 50 mL Schlenk flask equipped with a stirrer, 2.04 g (10.75 mmol) ofisobutylammonium isobutylcarbamate (white solid, melting point: 80-82°C.) was dissolved in 10 mL of methanol. 1.0 g (4.31 mmol) of silveroxide was added and reaction was performed at room temperature. Thereaction solution was initially a black slurry but it turned transparentas complex was produced. After 2 hours of reaction with stirring, acolorless, transparent solution was obtained.

The resultant solution was filtered with a 0.45 micron membrane filter.Then, the solvent was removed under vacuum to obtain white solid. Thesolid was dried and weighed to obtain 2.87 g of a silver complex(yield=94.4%).

Preparation Example 5

In a 50 mL Schlenk flask equipped with a stirrer, 1.60 g (10.75 mmol) ofisopropylammonium isopropylcarbamate (white solid, melting point: 78-80°C.) was dissolved in 10 mL of methanol. 1.0 g (4.31 mmol) of silveroxide was added and reaction was performed at room temperature. Thereaction solution was initially a black slurry but it turned transparentas complex was produced. After 2 hours of reaction with stirring, acolorless, transparent solution was obtained. The resultant solution wasfiltered with a 0.45 micron membrane filter. Then, the solvent wasremoved under vacuum to obtain white solid. The solid was dried andweighed to obtain 2.48 g of a silver complex (yield=95.5%).

Preparation Example 6

In a 50 mL Schlenk flask equipped with a stirrer, 3.27 g (10.80 mmol) of2-ethylhexylammonium 2-ethylhexylcarbamate (viscous liquid) wasdissolved in 10 mL of methanol. 1.0 g (3.60 mmol) of silver carbonatewas added. The reaction solution was initially a yellow slurry but itturned transparent as the reaction was performed. After 5 hours ofreaction, a yellow, transparent solution was obtained. The resultantsolution was filtered with a 0.45 micron membrane filter. Then, thesolvent was removed under vacuum to obtain white solid. The solid wasdried and weighed to obtain 4.18 g of a silver complex (yield=97.89%).

Preparation Example 7

In a 50 mL Schlenk flask equipped with a stirrer, 2.97 g (24.51 mmol) ofisopropylammonium bicarbonate (melting point: 53-54° C.) was dissolvedin 10 mL of methanol. 1.0 g (3.60 mmol) of silver oxide was added. Thereaction solution was initially a black slurry but it turned transparentas the reaction was performed. After 2 hours of reaction, a colorless,transparent solution was obtained. The resultant solution was filteredwith a 0.45 micron membrane filter. Then, the solvent was removed undervacuum to obtain white solid. The solid was dried and weighed to obtain2.41 g of a silver complex (yield=60.7%).

Preparation Example 8

In a 50 mL Schlenk flask equipped with a stirrer, 3.20 g (23.65 mmol) ofisobutylammonium bicarbonate (white solid) was dissolved in 10 mL ofmethanol. 1.0 g (4.31 mmol) of silver oxide was then added. The reactionsolution was initially a black slurry but it turned transparent as thereaction was performed. After 2 hours of reaction, a colorless,transparent solution was obtained. The resultant solution was filteredwith a 0.45 micron membrane filter. Then, the solvent was removed undervacuum to obtain white solid. The solid was dried and weighed to obtain3.21 g of a silver complex (yield=76.42%).

Examples Preparation of Resin Compositions Containing nano silverParticles

Resin compositions containing nano silver particles were prepared withvarying monomer, polymerization method and silver complex as Table 1below.

TABLE 1 Diameter of silver particle Polymerization Silver Sort Monomer(nm) method Initiator complex Example 1 Styrene 5-20 Bulk AIBNPreparation polymerization Example 1 Example 2 Styrene 5-20 Bulk AIBNPreparation polymerization Example 2 Example 3 Styrene 5-20 Bulk AIBNPreparation polymerization Example 3 Example 4 Methylmethacrylate 5-20Bulk AIBN Preparation polymerization Example 4 Example 5 2- 5-20 BulkAIBN Preparation hydroxyethylmethacrylate polymerization Example 5Example 6 Vinyl 5-20 Bulk DTBP Preparation Pyrrolidone polymerizationExample 5 Example 7 Vinyl 5-20 Bulk DTBP Preparation Pyrrolidonepolymerization Example 6 Example 8 Vinyl 5-20 Bulk DTBP PreparationPyrrolidone polymerization Example 7 Example 9 Styrene 5-20 SuspensionAIBN Preparation polymerization Example 1 Example Styrene 5-20Suspension AIBN Preparation 10 polymerization Example 2 ExampleMethylmethacrylate 5-20 Bulk DTBP Preparation 11 polymerization Example4 Example Methylmethacrylate 5-20 Bulk DTBP Preparation 12polymerization Example 8 Example 2-ethylhexylacrylate 5-20 Solution AIBNPreparation 13 butylacrylate polymerization Example 52-hydroxyethylmethacrylate

Example 1 Preparation of polystyrene Containing nano silver Particles

0.05 g of the silver complex of Preparation Example 1 was dissolved in18.4 g (0.172 mol) of styrene, a hydrophobic monomer.α,α′-azobisisobutyronitrile (1 mol % of the monomer), an initiator wasdissolved. The solution was put in a 50 mL polymerization ample and afreeze-thaw method was performed to remove gas, followed by sealing theample to perform radical polymerization at 70° C. for 24 hours.

After completion of the polymerization, the ample was opened and anobtained resin was heated at a final temperature of 140° C. to removevolatile decomposed product, thereby preparing final polystyrenecontaining nano silver particles.

Example 2 Preparation of polystyrene Containing nano silver Particles

Polystyrene containing nano silver particles was prepared by the samemanner as in Example 1, except that the silver complex of PreparationExample 2 was used instead of the silver complex of Preparation Example1.

Example 3 Preparation of polystyrene Containing nano silver Particles

Polystyrene containing nano silver particles was prepared by the samemanner as in Example 1, except that the silver complex of PreparationExample 3 was used instead of the silver complex of Preparation Example1.

Example 4 Preparation of polymethylmethacrylate Containing nano silverParticles

Polymethylmethacrylate containing nano silver particles was prepared bythe same manner as in Example 1, except that methylmethacrylate was usedas a monomer instead of the styrene and the silver complex ofPreparation Example 4 was used instead of the silver complex ofPreparation Example 1.

Example 5 Polyhydroxyethylmethacrylate Containing nano silver Particles

Polyhydroxyethylmethacrylate containing nano silver particles wasprepared by the same manner as in Example 1, except thathydroxyethylmethacrylate was used as a monomer instead of the styreneand the silver complex of Preparation Example 5 was used instead of thesilver complex of Preparation Example 1.

Example 6 Polyvinylpyrrolidone Containing nano silver Particles

0.05 g of the silver complex of Preparation Example 5 was dissolved in19.12 g (0.172 mol) of N-vinylpyrrolidone. Di-t-butylperoxide (1 mol %of the monomer), an initiator was dissolved. The solution was put in a50 mL polymerization ample and a freeze-thaw method was performed toremove gas, followed by sealing the ample to perform radicalpolymerization at 125° C. for 24 hours. After completion of thepolymerization, the ample was opened and an obtained resin was heated ata final temperature of 140° C. to remove volatile decomposed product,thereby preparing final polyvinylpyrrolidone containing nano silverparticles.

Example 7 Preparation of oolyvinylpyrrolidone Containing nano silverParticles

Polyvinylpyrrolidone containing nano silver particles was prepared bythe same manner as in Example 6, except that the silver complex ofPreparation Example 6 was used instead of the silver complex ofPreparation Example 5.

Example 8 Preparation of polyvinylpyrrolidone Containing nano silverParticles

Polyvinylpyrrolidone containing nano silver particles was prepared bythe same manner as in Example 6, except that the silver complex ofPreparation Example 7 was used instead of the silver complex ofPreparation Example 5.

Example 9 Preparation of polystyrene Containing nano silver Particles bySuspension Polymerization

0.5 g of the silver complex of Preparation Example 1 andα,α′-azobisisobutyronitrile (1 mol % of the monomer), an initiator werecompletely dissolved in 90.2 g (0.86 mol) of styrene and thendegasified. The solution was dropped in 500 g of a solution, in which 5wt % of barium sulfate and 5 wt % of polyvinylalcohol (mean molecularweight, Mw: 50000) as a stabilizer were dissolved, under nitrogen streamwith stirring at a speed of 44 rpm to perform dispersion. Radicalpolymerization was performed at 70° C. for 24 hours with continuousstirring. After completion of the polymerization, the polymerizedproduct was left for 1 hour and then filtered to remove precipitate. Theobtained nanoparticulate polystyrene resin was treated at 130° C. for 30minutes, thereby obtaining final polystyrene containing nano silverparticles.

Example 10 Preparation of polystyrene Containing nano silver Particlesby Suspension Polymerization

Polystyrene containing nano silver particles was prepared by the samemanner as in Example 9, except that the silver complex of PreparationExample 2 was used instead of the silver complex of Preparation Example1.

Example 11 Preparation of polymethylmethacrylate Containing nano silverParticles by Bulk Polymerization

Di-t-butylperoxide (0.2 mol % of the monomer), a radical initiator and0.5 g of silver complex of Preparation Example 4 were completelydissolved in 90.0 g (0.900 mol) of methylmethacrylate. The solution wasput in a 500 mL three necked round bottom flask equipped with acondenser, a nitrogen injection pipe and a stirrer and the flask wasthen substituted with nitrogen. After that, polymerization reaction wasperformed for 30 minutes at 80° C., for 50 minutes at 85° C., for 4hours at 60° C., for 6 hours at 95° C. and for 1 hour at 130° C. to abulk polymer of polymethylmethacrylate.

Example 12 Preparation of polymethylmethacrylate Containing nano silverParticles by Bulk Polymerization

Polymethylmethacrylate containing nano silver particles was prepared bythe same manner as in Example 11, except that the silver complex ofPreparation Example 8 was used instead of the silver complex ofPreparation Example 4.

Example 13 Nano silver Particles Dispersed acryl Resin by SolutionPolymerization of acryl

30 g of 2-ethylhexylacrylate, 30 g of butylacrylate, 6 g of2-hydroxyethylacrylate and 2.78 g of isopropylammonium carbamate weredissolved in 81 g of ethylacetate and 28 g of methylalcohol. 0.01 g ofα,α′-azobisisobutyronitrile, an initiator was put and initial reactionwas performed with 20 minutes of stirring. After that, as apolymerization step, a mixture solution of 89 g of2-ethylhydroxyacrylate, 89 g of butylacrylate, 20 g of2-hydroxyethylacrylate, 101 g of ethylacetate, 52 g of methylalcohol and0.5 g of α,α′-azobisisobutyronitrile was dropped for 90 minutes,followed by 90 minutes of stirring. In a termination step, a mixturesolution of 50 g of ethylacetate, 50 g of methylalcohol and 1 g ofα,α′-azobisisobutyronitrile was dropped for 60 minutes, followed by 180minutes of stirring. Finally, 200 g of ethylacetate and 120 g ofmethylalcohol were put, followed by 20 minutes of stirring to preparesilver dispersed acrylic synthetic resin composition having a solidcontent of 35 wt %.

To confirm a dispersibility of the resin compositions containing nanosilver particles, a sample solid thin film was prepared using an ultrasawing machine. The polymethylmethacrylate prepared in Example 4 and thepolyvinylpyrrolidone prepared in Example 6 were dissolved in toluene andlaid on a grid and observed with Transmission Electron Microscope (TEM,model: JEOL JEM-2000 FXII), respectively. The results were shown inFIGS. 1 and 2, respectively. As shown in FIGS. 1 and 2, it could beappreciated that the resin compositions prepared according to thepresent invention have uniformly sized and uniformly dispersed silverparticles.

INDUSTRIAL APPLICABILITY

As described above, the present invention provides a method forpreparing resin compositions containing uniformly dispersed nano silverparticles by dissolving a silver complex having a specific structure inat least one vinyl monomer and performing polymerization.

The silver complex according to the present invention is decomposed tosilver, amine and carbon dioxide by heat applied during thepolymerization and nano silver particles are produced simultaneouslywith the polymerization. This silver complex has a solubility in vinylmonomer having various polarities according to a length and chemicalstructure of alkyl group in the amine and it is therefore possible toprepare homopolymer and copolymer in which various nano silver particlesare dispersed. Also, the dispersibility of the nano silver particles isvery high and it is therefore possible to prepare a synthetic resin inwhich silver nanopartices of high concentration are uniformly dispersed.

Further, the method for preparing resin compositions containing nanosilver particles may be applied in various polymerization methods suchas a bulk polymerization, a subspension polymerization and a solutionpolymerization and it is therefore possible to prepare resin compositioncontaining nano silver particles usable for various uses.

Furthermore, the resin composition containing nano silver particlesaccording to the present invention is an antibiotic resin and it istherefore possible to provide a superior composition usable for watersuppling pipe, an antibiotic container for a refrigerator, a materialfor electromagnetic wave shielding and an antistatic coat. When theconcentration of the nano silver particles complex is increased, it ispossible to reduce the number of process steps by a master batch inwhich the nano silver particles are mixed in a material for a generalpurpose synthetic resin with increased concentration. Therefore, it iseconomic and cost- and process time-saving.

Those skilled in the art will appreciate that the conceptions andspecific embodiments disclosed in the foregoing description may bereadily utilized as a basis for modifying or designing other embodimentsfor carrying out the same purposes of the present invention. Thoseskilled in the art will also appreciate that such equivalent embodimentsdo not depart from the spirit and scope of the invention as set forth inthe appended claims.

1. A method for preparing resin compositions containing nano silverparticles, comprising: dissolving a silver complex prepared by reactinga silver compound represented by the formula 1 below with one or amixture of two or more selected from the group consisting of ammoniumcarbamate-based compound, ammonium carbonate-based compound and ammoniumbicarbonate-based compound represented by the formula 2 to 4, in a vinylmonomer; and radically polymerizing the vinyl monomer,

wherein, in the formulas 1 to 4, X is a substituent selected from thegroup consisting of oxygen, sulfur, halogen, cyano, cyanate, carbonate,nitrate, nitrite, sulfate, phosphate, thiocyanate, chlorate,perchlorate, tetrafluoroborate, acetylacetonate, carboxylate andderivatives thereof, n is an integer from 1 to 4, R₁ to R₆ areindependently selected from the group consisting of hydrogen, hydroxylgroup, C₁-C₃₀ alkoxy group, C₃-C₂₀ aryloxy group, C₁-C₃₀ aliphatic orC₃-C₂₀ cycloaliphatic alkyl group or C₃-C₂₀ aryl or C₄-C₃₀ aralkyl groupas a mixture thereof, substituted C₁-C₃₀ alkyl group, substituted C₃-C₂₀aryl group, substituted C₄-C₃₀ aralkyl group, C₃-C₂₀ heterocycliccompound including a heteroatom selected from the group consisting of N,S and O, polymer compound and derivatives thereof, wherein when R₁ to R₆are substituted or unsubstituted alkyl group or aralkyl group, alkylgroup or aralkyl group may contain a heteroatom selected from the groupconsisting of N, S and O, or an unsaturated bond in the carbon chain,wherein R₁ and R₂ or R₄ and R₅, independently, may form an alkylene ringcontaining or not containing a heteroatom.
 2. The method as set forth inclaim 1, wherein the silver compound of the formula 1 is one or amixture of two or more selected from the group consisting of silveroxide, silver thiocyanate, silver cyanide, silver cyanate, silvercarbonate, silver nitrate, silver nitrite, silver sulfate, silverphosphate, silver perchlorate, silver tetrafluoroborate, silveracetylacetonate, silver acetate, silver lactate, silver oxalate and aderivative thereof.
 3. The method as set forth in claim 1, wherein R₁ toR₆ are independently selected from the group consisting of hydrogen,methyl, ethyl, propyl, isopropyl, butyl, isobutyl, amyl, hexyl,ethylhexyl, heptyl, octyl, isooctyl, nonyl, decyl, dodecyl, hexadecyl,octadecyl, docodecyl, cyclopropyl, cyclopentyl, cyclohexyl, allyl,hydroxy, methoxy, hydroxyethyl, methoxyethyl, 2-hydroxypropyl,methoxypropyl, cyano ethyl, ethoxy, butoxy, hexyloxy,methoxyethoxyethyl, methoxyethoxyethoxyethyl, hexamethyleneimine,morpholine, piperidine, piperazine, ethylenediamine, propylenediamine,hexamethylenediamine, triethylenediamine, pyrrole, imidazole, pyridine,carboxymethyl, trimethoxysilylpropyl, triethoxysilylpropyl, phenyl,methoxyphenyl, cyanophenyl, phenoxy, tolyl, benzyl polyallylamine,polyethyleneimine and a derivative thereof.
 4. The method as set forthin claim 3, wherein the ammonium carbamate-based compound of the formula2 is one or a mixture of two or more selected from the group consistingof ammonium carbamate, ethylammonium ethylcarbamate, isopropylammoniumisopropylcarbamate, n-butylammonium n-butylcarbamate, isobutylammoniumisobutylcarbamate, t-butylammonium t-butylcarbamate,2-ethylhexylammonium 2-ethylhexylcarbamate, octadecylammoniumoctadecylcarbamate, 2-methoxyethylammonium 2-methoxyethylcarbamate,2-cyanoethylammonium 2-cyanoethylcarbamate, dibutylammoniumdibutylcarbamate, dioctadecylammonium dioctadecylcarbamate,methyldecylammonium methyldecylcarbamate, hexamethyleneiminiumhexamethyleneiminecarbamate, morpholinium morpholinecarbamate,pyridinium ethylhexylcarbamate, triethylenediaminiumisopropylbicarbamate, benzylammonium benzylcarbamate,triethoxysilylpropylammonium triethoxysilylpropylcarbamate and aderivative thereof, the ammonium carbonate-based compound represented bythe formula 3 is one or a mixture of two or more selected from the groupconsisting of ammonium carbonate, ethylammonium ethylcarbonate,isopropylammonium isopropylcarbonate, n-butylammonium n-butylcarbonate,isobutylammonium isobutylcarbonate, t-butylammonium t-butylcarbonate,2-ethylhexylammonium 2-ethylhexylcarbonate, 2-methoxyethylammonium2-methoxyethylcarbonate, 2-cyanoethylammonium 2-cyanoethylcarbonate,octadecylammonium octadecylcarbonate, dibutylammonium dibutylcarbonate,dioctadecylammonium dioctadecylcarbonate, methyldecylammoniummethyldecylcarbonate, hexamethyleneiminium hexamethyleneiminecarbonate,morpholinium morpholinecarbonate, benzylammonium benzylcarbonate,triethoxysilylpropylammonium triethoxysilylpropylcarbonate,triethylenediaminium isopropylcarbonate and a derivative thereof, andthe ammonium bicarbonate-based compound represented by the formula 4 isone or a mixture of two or more selected from the group consisting ofammonium bicarbonate, isopropylammonium bicarbonate, t-butylammoniumbicarbonate, 2-ethylhexylammonium bicarbonate, 2-methoxyethylammoniumbicarbonate, 2-cyanoethylammonium bicarbonate, dioctadecylammoniumbicarbonate, pyridinium bicarbonate, triethylenediaminium bicarbonateand a derivative thereof.
 5. The method as set forth in claim 1, whereinthe silver complex is prepared by adding carbon dioxide to aminecompound corresponding to one of the compounds of the formulas 2 to 4 toprepare corresponding ammonium carbamate-based compound, ammoniumcarbonate-based compound or ammonium bicarbonate-based compound, andreacting the prepared compound with the silver compound of theformula
 1. 6. The method as set forth in claim 1, wherein the vinylmonomer is one or a mixture of two or more selected from the groupconsisting of alkyl group-containing vinyl monomer, hydroxylgroup-containing vinyl monomer, N-substituted amide-based vinyl monomer,alkoxyalkylacrylate-based vinyl monomer, cyanoacrylate monomer, epoxygroup-containing acrylic monomer, acrylic acid ester monomer.
 7. Themethod as set forth in claim 1, wherein the vinyl monomer is one or amixture of two or more selected from the group consisting ofmethylacrylate, methylmethacrylate, ethylacrylate, ethylmethacrylate,propylacrylate, propylmethacrylate, butylacrylate, butylmethacrylate,hexylacrylate, hexylmethacrylate, octylacrylate, 2-ethylhexylacrylate,hydroxyethylacrylate, hydroxyethylmethacrylate, hydroxypropylacrylate,hydroxypropylmethacrylate, hydroxybutylacrylate,hydroxybutylmethacrylate, hydroxyhexylacrylate,hydroxyhexylmethacrylate, N,N-dimethylacrylamide,N,N-dimethylmethacrylamide; methoxyethylacrylate,methoxyethylmethacrylate, ethoxyethylacrylate, ethoxyethylmethcrylate,vinylchloride, vinylidene chloride, vinylfluoride, vinylidene fluoride,vinylacetate, vinylpropionate, N-vinylpyrrolidone,methylvinylpyrrolidone, vinylpyridine, vinylpiperidone, vinylpyrimidine,vinylpiperazine, vinylpyrazine, vinylpyrrole, vinylimidazole,vinyloxazole, vinylmorpholine, N-vinylcarboxamides, styrene,α-methylstyrene, N-vinylcaprolactam, acrylonitrile, methacrylonitrile,glycidylacrylate, glycidylmethacrylate, ethyleneglycolacrylate,ethyleneglycolmethacrylate, prop yleneglycolacrylate,propyleneglycolmethacrylate, methoxyethyleneglycolacrylate,methoxyethyleneglycolmethacrylate, methoxypropyleneglycolacrylate,methoxypropyleneglycolmethacrylate, tetrahydrofurfuryl acrylate,tetrahydrofurfuryl methacrylate, 2-methoxyethyl acrylate, isoprene,butadiene, isobutylene and vinyl ether, diallylphthalate anddiallylcarbonate.
 8. The method as set forth in claim 1, furthercomprising performing heat treatment at 40 to 200° C. after the radicalpolymerization.
 9. A resin composition containing nano silver particlesprepared by the method for preparing resin compositions containing nanosilver particles as set forth in claim 1.